JK Rowling to publish new Harry Potter story for Halloween

JK Rowling is set to publish a special Harry Potter story on her website as a Halloween surprise for fans.

The original tale will focus on cruel Hogwarts professor Dolores Umbridge, the witch who first appeared in Harry Potter and the Order of Phoenix as the Minister for Magic's Senior Undersecretary, played by Imelda Staunton in the films.

Umbridge memorably ordered young wizard Harry to use a Blood Quill and scar himself with the phrase, "I must not tell lies".

"Umbridge is not only one of the most malicious Potter characters, she is the only person other than Lord Voldemort to leave a permanent physical scar," reads a statement on Pottermore.com.

The website dropped a few hints for fans, promising a "rich, 1700-word back story about Umbridge's life, filled with many new details, as well as Rowling's revealing first-person thoughts and reflections about the character".

The story is expected to appear online on Friday 31 October.

Rowling released another Harry Potter story online last July, which saw a 33-year-old, greying Harry reunite with Ron Weasley, Hermione Grainger, Luna Lovegood and Neville Longbottom for the final of the Quidditch World Cup. It attracted so much traffic that Pottermore temporarily crashed.

Earlier this week, Rowling was forced to debunk rumours that she has recently finished a romantic novel.

Newspaper reports suggested she had been "celebrating" the book's completion in a London bar, but the allegations proved false.

"I sometimes have a drink even when I haven't finished a book," she wrote on Twitter. "Yes, that's how rock and roll I really am."

Instead, Rowling is "halfway through" writing another novel, which is not a romance and believed to be a follow-up to 2011's The Casual Vacancy.